Stapling machine



Oct. 23, 1928.

F. POLZER STAPLING MACHINE Filed Feb. 24, 1928 ,VVI mnd a /D Patented oa. 23, 192s.-

-NiTED STATES ,PATENT ortica.

NRIDOLIN rOLzER, oF NORWALK, CONNECTICUT, AssiGNOR To THE E, n. HOTCHKISS COMPANY, OF NORWALK, CONNECTTCUT. A conroiaa'iiioN or CONNECTICUT.

STAPLING MACHINE.

Application led February 24, 1928. Serial No. 256,556.

rihis Iinvention relates to staple driving machines particularly of the type in which substantially U-shaped .staples are severed one at a time from a strip of connected staples and driven. The mechanism is adapted for use either in a so-called stapling machine in which the staples are clinched, or in a socalled tacler. in which the staples are ine-rely driven into the work. n

It is a particular object of the invention to provide an improved means for1 holding and guiding the first staple on the strip during the severing and driving operation to prevent its turning out of the upright position and becoming jammed in the raceway, 'and also toprovide improved means for holding the strip against backward movement either under retrograde movement of the feeding device or other means.

With the foregoing and other o bgects in view, I have devised the construction ill ustrated in the accompanying drawing forming a part of this specification. In thisl drawino' A Fig. 1 is aside elevation o-f the mechanism with one side of the main housing removed and a portion of the plunger housing being shown in section.

Fig. 2 is a horizontal section on an enlarged scale 'taken substantially on 1 line 2-2 of Fig. 1.

^ Fig. 3 is a vertical detail transverse section at the forward part of the staple strip .slide bar taken substantially on line 3-3 ofFig. 2.

Fig.` 4 is a similar section taken substantially on line 4 4 of Figs. 1 and 2, and

Fig. 5 is a detail elevation looking toward the inside of one side of the main 'housing showing the means for mounting the staple holding and guiding means.

The main ho-using compri-Ses inner and out-er pilates 1'0 and 11 respectively, in the prese-nt case stamped from sheet metal and .are placed in nested relation as indicated, and

the outer plates have inwardly extending flanges 12 and 13 which are arranged 'in abutting relation, the outer flanges serving to close the back of this housing and the inner flanges 13 serving to form the side walls of a handopenin'g providing a hand grip. Mounted in a removable housing 14 secured at the front of the machine is a vertically reciprocable plunger 15 having la cutting edge at its lower end 16 adapted to cooperate with thefront upper edge of the staple strip slide sage of the prongsof the staples. The plungl er .has lateral ribs 21 'which assist in. guiding this -plunger for vertical movement in its housing, and theyl are also in alignment with the prongs of the staple to assist in driving the staple. The 'plunger is forced downwardly for the severing and driving Operation by a spring 2 2, the tension of which ma be adJusted by adjustingtiie cap 23 threaded on the outside of the pluiigtii housing, and the downward movement of the plunger is arrest* ed at a certain point by a coil spring 24 einbracing the lower part of the plunger and adapted at its upper end to engage a shouL der 25 on the plunger just before the plunger reaches its lowest position. This spring will thus form a cushion stop for the plunger and absorb shocks should the plunger be operated without driving staples.

Mounted in the main housing on a pivot 26 is a hand lever 27. -This lever carries a pivoted catch or pawl 28 having a nose 29 adapted to engage under a shoulder 30 on the plunger so that when the free end of the lever is depressedit will raise the plunger against the action of the driving spring l22.y When the plunger reaches its upper position this pawl will slide ofi` the shoulder, releasing the plunder and permitting it to be forced down- Ward-ly under action of the spring. The pawl is pivoted to the lever at 31 and its nose is held against the plunger by spring 32 so that when the lever 27 is moved upwardly the free end of the pawl may yieldto pass under the shoulder 30. The hand `lever 27 also carries an extension 33`which is connected to one end of a coil spring 34. At its other end this spring is connected to areciprocable feed bar 35 mounted to slide,on a support 36. This support 36 is a'strip of metal extending transversely between the sides of the housing and having lugs 37 seated in openings in the side walls of the housing. The feed bar 35 is guided between thesupport and -inwardly ex- MIU is bent upwardly, as shown at 39, and cooperates with an inclined cam surface on the plunger so that as the plunger comes down this cam surface by enga-ging the end of the feed bar will force the feed bar `backwardlyea distance corresponding to the distance tween two staples on the strip in preparation for the next feeding movement of the staple strip. This feed bar carries a downwardly extending feed pawl 41 adapted to engage at its forward end the rear edges of the cross bar of successive staples to advance the staple strip step by step to bring the staples successively into the driving position under the plunger. The support 36 may carry a down-v wardly extending spring finger 424 engaging the top of the staple strip to assist'in holdin g it in proper position on the slide bar.

The forward ends of the spacing members 19 are terminated short of or lat a distance from the front end 43 of the slide bar, as shown at 19', to provide clearance spaces 44 between the sides of the slide bar and the inner walls l of the housing and extending throughout the height of `this bar to provide a clearance space for the prongs of the staples should they bend out of position. This will prevent their jamming in the raceway and will permit easy clearing of the machine because they permit the bent staples to either drop out of the machine or be forced out by the lunger.

ounted in these clearance spaces are spring operated ieldable holding fingers 45 for t-he staple eing severed and driven. These fingers are preferably of spring metal and are secured to the side walls of the housing at the outer side of the staple prongs. They are bent inwardly at their forward ends to form an upright guiding and holding rib 46 which is adapted to move inwardly between the firstiand second staples into alignment with the rear edge of the prongs of the first staple 47 when it is in a. position for driving an prevent these prongs from turning backwardly under the action of the plunger or for any other reason. These guide ribs 46 preferably extend substantially throughout the entire height of the slide bar, as shown in Figs. 3 and 5, so as to uide the staple being d-riven throughout su stafntially its entire movement. Improvedmeans for mounting these fingers comprises providing the inner plates 10 with an elongated opening 48 and to the right hand of this opening a vert-ical slot 49. The outer plates 11 of the housing are forced outwardly somewhat, as indicated at50, to form a groove on the inner side of this plate. The end of the lingers 45 are bent outwardly through the openings 48. extended in the rec'ess formed by the bulge 50 in the inner plate 10 so that it is located between the plates, and then the free end 51 extends inthat when the plates 10 and 11 are assembled these fingers are securely held in position without any riveting operation and they may be easily .removed for renewal.

Improved means are also provided for preventing backward or retrograde movement under the action of the feed pawl when it is retracted for preparation for the feeding operation, or for any other means. For this purpose I have provided a spring finger 52 on each side of the slide bar 17 so that they are on the inside of the staple strip. At their forward ends they are bent outwardl somewhat, as shown at 53 to provide liolding pawls adapted to move outwardly to a position`in alignment with the rear edges of the prongs of the second staple 54 and to engage these prongs to hold the staple against back- .ward movement. These fingers are preferably mounted in longitudinal .recesses 55 formed in the side walls of the slide bar 17 and may be mounted therein by any suitable means, such as a rivet 56.

The operation is as follows: The elements are normally inthe posit-ion of Fig. 1. When the levcr 27- is depressed the pawl 28 will lift the plunger 15 against the action of the operating spring 22. This action of the lever will 4also tension or increase the tension of the feed spring 34. As soon as the lower end of the plunger is moved to apposition above the lslide bar 17 the feed s ring 34 will force the feed bar 35 forwar ly, which movement throu the feed pawl 41 will force the staple strip orwardly and bring the rst staple 47 on the strip to a position under the plun r in the raceway, as shown in dotted lines, i0'.

-2. During this movement of the staple strip the forward ends of the holding fingers 45 will yield laterally outward permitting the forward staple to advance into the raceway, and they will then move inwardly to the position of Fig. 2 with the guiding rib 46 just behind the prongs of the first staple to form I a vertical guide for these rongs at the rear side thereof. During thisY orward movement of the sta le strip the forward ends of the holdback. ngers 52 yield inwardly to permit the prongs of the second staple 54 to pass, and then these free ends spring outwardly, as shown in Fig. 2, so as to lie immediately to the rear of the rear edges of the prongs of the second staple 54 and will hold the staple strip against backward movement, either under action of the plunger, the feeding means or other mea-ns. When the plunger reaches a certain position it is released by the pawl 28 and is orced downwardly by its operating p unger causes its lower end to sever the first staple from the stri and to drive it into spring 22. This downward movement of the the work. `During thls operation the vertical v l guide ribs 46 of fingers 45 will provide a holding and guiding means and revent the staple turning baclxwardly ont ol its proper a staple strip slide bar in the housing, amovable plunger for driving the individual staples, means for operating the plunger, means for feeding the staple to driving position, means on the outside ofthe staple strip to enter behind first staple on the strip when in driving position to prevent the prongs from turning back, and holdback means mounted on the slide bar inside the staple chine comprising a housing, a staple strip slide bar, a reciprocable plunger forvdriving the staples, means for operating the plunger, and feeding means for the staple strip; of spring fingers secured'to the housing at the opposite sides of the slide bar having inwardly bent free ends adapted to enter between the first and second staples on the strip and hold the prongs 1of the first staple from turning backward and guiding the same during the driving operation, and spring fingers mounted on opposite sides of the slide bar and provided with free ends adapted to move outwardly to a position between the second and third staple to prevent backward movement of the strip. il

4. In a staple driving machine, a housing, a staple strip slide bar mounted i n the housing, a reciprocable plunger mounted to move across the front end of the slide bar to drive strip to engage the rear edge of the second/the individual staples, areciprocable feed de- 'staple to prevent retrograde movement of the staple strip.

2. The combination in a staple driving machine comprising a housing, a staple strip slide bar, a reeiprocable plunger for driving the staples, means for operating the plunger,

-eldably mounted fingers secured to the ousing and having a vertical front end adapted to enter behind the legs of the first staple when in driving position to prevent movement of the strip.

the staple bending backwardly, and yieldably mounted fingers secured to the slide bar and ada ted to engage the rear edge of the legs of t e second staple to prevent backward 3; The combination in a staple driving maand feeding 'means' for the staple strip; of.

vice for advancing the staples on said slide to the driving position, said slide being provided with longitudinally extending recesses in the opposite side walls thereof, spring op erated holdback fingers mounted in said recesses and provided with shoulders adapted. to engage the rear 'edges of the prong's of the second staple on the strip to prevent retrograde movement thereof, and spring operated fingers mounted in the housin outside the i staple strip and provided wit shoulders adapted to move inwardly to a position back of the prongs of the first sta le on the strip to hold and guide this staple during the driving operation.

In testimony whereof I afix my signature.v

' FRIDOLIN POLZERQ 

